A run-out period is a timeframe in the new plan year during which you can file claims for expenses incurred in the previous plan year. This timeframe is established by your employer—not the IRS. While timeframes vary from employer to employer, a 90-day run-out period is common. If your plan year ends on December 31, and you have a 90-day run-out period, you have until March 31 of the following plan year to use money left in your Healthcare FSA.
To confirm if your plan offers a run-out log into your online account. To see your plan filing dates hover your cursor over the i (information) icon next to the plan name.